Sub-miniature tube socket



Nov. 15, 1955 M. A. RUDNER 2,724,095

SUB-MINIATURE TUBE socxm Filed Oct. 6, I952 FIG.9

INVENTOR. Merritt A. Rudner g ATTORNEY United States PatentOSUB-MINIATURE TUBE SOCKET Merritt Allen Rudner, Haddonfield, N. J.,assignor to United States Gasket Company, Camden, N. J., a corporationof New Jersey Application October 6, 1952, Serial No. 313,225

3 Claims. (Cl. 339-192) This invention relates to electronic tubesockets, and particularly to sub-miniature tube sockets.

The miniaturization of electronic components for both military andcivilian uses has presented a problem of making very small or miniatureelectron tubes, and, C011? sequently, very small or miniature tubesockets for receiving those tubes, to establish appropriate electricalconnections to the circuits in which the tubes are to be utilized.

A tube socket in the accepted conventional form consists of a body ofinsulating material with suitable recesses for accommodating severalmetallic terminal elements, that are suitably anchored to the insulatingmaterial. Each such element usually has, a hollow body portion toreceive and to resiliently grip a terminal pin of the electron tube. ingtail piece portion to serve as a terminal for receiv- Each body portionhas an extending an electrical connection to a conductor from anexternal circuit to which the corresponding pin of the electron tube isto be connected.

The recesses or cavities that are formed in the body of insulatingmaterial must be suitably separated to keep the metallic terminalelements insulated from each other. That is ordinarily done by providinga thin wall of the insulating material between the spaces or cavitiesfor the pin-gripping bodies of the terminal elements. In order to keepthe overall dimensions of the socket within desired prescribed limits,and to distribute the cavities or recesses at appropriate spacings toreceive the'pins of the miniature or sub-miniature electron tubes, theinsulating walls between the spaces become so thin that it is difficultto assure their complete and proper formation by adequate fiow of theplastic material in the usual injection mold process that has beenheretofore used for the purpose of making such sub-miniature sockets ofthermosetting materials.

Among the resins that have suitable and desirable insulating qualitiesare the fiuoro-carbon resins. Their chemical, physical and electricalcharacteristics make them suitable materials for many applications,particularly for use as insulating materials or supports for electricalcontacts or terminals. One of these materials, polytetrafluoroethyleneis made and sold under the trademark Teflon; and another material,polymonochlorotrifluoroethylene is sold under the trademark KEL-F.

For convenient reference, the trademark will be used to refer to thespecific material, with the understanding that the material itself isintended.

One of the striking physical characteristics of Teflon and of KELF istheir ability to resist wetting or sticking. They are impervious toWater and moisture. The resistivity of these materials is very high.Their power factor is low. Those characteristics combine to make thesematerials excellent base materials for electronic applications.

I These materials are provided in their raw state as powders, which maybe formed and molded by pressure and heat to any simple shapes that maybe desired. The

2,724,095 Patented Nov. 15, 1955 materials may also be formed in bar orsheet stock and then machined to shape, where complex shapes are desiredthat may not be readily adapted to simple molding or extrudingoperations, for example.

The characteristics of these fluoro-carbon resin materials make themideal bases for miniature or subminiature base tube sockets.

One object of this invention is to provide one or more forms ofconstruction that will permit the utilization of these fluoro-carbonresin compounds, and particularly Teflon, as the insulating base supportfor the pin terminals that are to receive and grip the pins of a subminiature electron tube.

Another object of this invention is to provide a subminiature tubesocket in which the separating walls between cavities of the socketshall be always completely formed during the manufacturing process,thereby assuring minimization or elimination of rejects for that reason,and further assuring a substantially solid wall structure that willprovide adequate and proper strength and insulation in the final tubesocket.

Another object of this invention is to provide a novel structure forsuch a sub-miniature tube socket, together with a novel method of makingthe socket.

Another object of this invention is to provide a subminiature tubesocket of novel design, in which the socket may be composed of two ormore individual sections that can be individually made with an assuranceof substantial dimensional control, within satisfactory tolerancelimits, and the parts then fitted together with an assurance of properinter-fitting physical dimensions for maximum physical strength andelectrical insulation.

The manner in which a sub-miniature tube socket is constructed,according to the principles of this invention is illustrated in theaccompanying drawings, in which Figure 1 is a plan view of two insulatorsections shaped with mortise grooves and tenon extensions for assemblyin close-coupled fitting relationship to provide in-line spaces orcavities for accommodating pin-receiving terminal elements;

Figure 2 is front elevational view of one of the elements shown inFigure 1;

Figure 3 is a bottom plan view of an encircling or corseting band forholding the two elements of Figure 1 in closely interfitted operativerelation;

Figure 4 is a side elevational view, partly broken away, of the band ofFigure 3;

Figure 5 is a perspective view showing portions of the two elements ofthe socket of Figure 1, assembled in tight interfitting operatingrelationship, and disposed in and confined by the encircling band ofFigures 3 and 4,- with one pin-receiving terminal element in place inone cavity;

Figure 6 is a plan view of a second modification of a sub-miniature tubesocket, in which the socket consists of an outer ring and central plug,to provide terminal spaces arranged in a circle;

Figure 7 is a vertical sectional view of the plug and outer ring ofFigure 6, held within an encircling band having a mounting bracket;

Figure 8 is a perspective view of a portion of the plug and a portion ofthe outer ring, showing how. they are to interfit to define a cavity orspace to receive a pin-receiving terminal;

Figure 9 is a side elevation of a pin-terminal as used in the socket;and

Figure 10 is an enlarged plan View of a portion of the assembled socketof Figure 6, to show the disposition of a pin terminal in a cavitybetween the central plug and the ring of the socket.- 5 As shown inFigure 1, one form of sub-miniature socket 10 consists of twocomb-shaped elements 11 and 12, whose inner facing walls 11a and 12a,respectively, are provided with mortise cavities 13 and tenons or teeth14 on element 11, and with cavities 15 and tenons or teeth 16 on element12. The cavities and the tenons are of corresponding width, to permitthe two elements 11 and 12 to be snugly fitted together.

The cavities 13 and the tenons 14 of the narrower element 11 areshallower and shorter than the cavities 15 and the tenons 16 of themating element 12. Thus, when the two elements 11 and 12 are mated andpressed to closefitting position, the longer tenons 16 are pressed homein the short cavities 13, but the short tenons 14 remain spaced from thebackwalls 17 of the long cavities 15. The spaces 18 (Figures 2 and thusdefined between the ends of the short tenons 14 and the back walls 17 ofthe long cavities serve to accommodate pin-receiving contact terminals19 for receiving and gripping the pins of sub-miniature tubes that areto be received by the sub-miniature socket.

As shown in Figure 9 the pin-receiving contact terminal 19 consists ofan upper forked element 21; having two prongs or fingers mounted toembody a certain amount of resilience and spaced a distance justslightly less than the thickness of the pin of a sub-miniature tube, sothe pin will be tightly and resiliently gripped by the prongs of theforked element 21) of the contact terminal 19. A tail piece 21 extendsdownwardly from the fork 20, and provides the terminal portion to whicha conductor from an external circuit may be soldered or otherwisetightly connected to establish the desired circuit connection for thecorresponding pin of the electron tube which is inserted into thesub-miniature socket. 7

When the tenon-and-grooved elements 11 and 12 are assembled in matedinterfitting position, they are then pressed into an encircling andconfining band 22 (Figures 3 and 4) which is formed as a slightly ovalring or shell 23 with an upper rim flange 24 provided with two or moreholes 25 and 26 to serve to receive holding-down screws, to anchor theshell together with its insulating socket elements in place wheredesired.

The bottom rim edge 27 of the shell 23 is peened radially inwardslightly to retain the fitted elements 11 and 12 against expulsion fromthe shell when an electron tube is pressed to force its pins into thecontact forks 20. The band 23 is otherwise sufficiently tight in itself,around the two elements 11 and 12, to retain them against exiting fromthe band when an electron tube is being removed from the socket.

One of the characteristics of the fluoro-carbon resins, and particularlyof the Teflon resin, is its limited amount of compressibility andresiliency. Consequently, when the two sections 11 and 12 are forcedunder pressure into the confining metal shell 23, the metal shell 23serves to tightly grip the two elements, both to hold those two elements11 and 12 in proper relative position, and also to hold those twoelements against removal when an electron tube is pulled out of thesocket.

ter the two comb'shaped elements 11 and 12 are assembled and mated, thecontact terminals 19 may be installed. One such terminal 19 is shown inFigure 5. That Figure 5 also shows the ledge or shelf 29 that serves asa floor to support the fork 20 of the contact terminal 19.

Each space 18 is thus defined between the long tenons 16 and between thefront ends of the short tenons 14 and the back walls 17. The space 18has an upper compartment 18a to accommodate the fork 29 of the contactterminal above the shelf or fiocr 29, and has a lower passage 18b,passing the shelf 29, to permit the tail-piece 21 of the contactterminal to be extended therethrough for proper disposition and seatingof the fork 26 of the contact terminal 19. After the terminal isproperly inserted and seated, the tail-piece 21 is folded to form adouble rightangle bend, immediately against the under sides of the twocomb-shaped elements 11 and 12, alternately, to space the ends of thetail-pieces and make them more conveniently accessible for soldering aconnection to each of them, and to provide more spacing as insulation.

In Figures 6 and 7, a second modification 30 of a subminiature tubesocket is shown, in which the pin terminals are arranged in a circle.The sub-miniature socket 36 comprises an outer ring element 31 and acentral plug 32. The outer ring element 31 is provided with mortisecavities 33 for receiving the tenons 34 of corresponding width, formedon the central plug element 32. As in the first modification shown inFigure l, the tenons in this case are somewhat shorter than the depth ofthe cavities 33 into which they fit, in order to provide a small butdefinitely defined cavity space or pocket 35a between each tenon 34 andthe back wall 35 of the mortise cavity 33, for accommodating apin-receiving contact terminal 19 such as shown in Figure 9.

As shown in more detail in the sectional view of Figure 7, the outerdiameter of the circular peripheral surface of the central plug element32 between the tenons 34, and along the lower part of the plug body, ismade somewhat larger than the normal inner diameter of the regularsurface of the outer ring element 31. Along its upper edge, the plug 31is slightly indented between the tenons 34 to embody a curved seat 36.

The outer ring element 31 is formed to embody a radially inwardlyextending shoulder 37 along and around its bottom region, to serve as ashelf for the central element or plug 32, and to serve as a proper stoplimit for that central plug element 32 when it is inserted into theouter ring 31 and assembled to constitute the sub-miniature structure.

- By reason of that larger diameter of said central plug 32, the arcuatesegments 38 between the mortise cavities 33 and along the upper inneredge of the outer ring element 31, will first be pressed back, out ofthe way of the plug 32 when the plug is assembled within the outer ring31, and until the plug is pressed home, down against shelf 37. Thearcuate segments 32 will then resume their positions and move radiallyinwardly over the top seat edge 36 of the central plug 32.

The resiliency and the tensile and shearing strength of thefiuoro-carbon resin material, particularly the Teflon material, issuflicient to permit the entire ring 31 to be expanded slightly, bycentrifugal pressure of the plug, and particularly the centrifugalradial pressure against the arcuate sections 38 will deflect them toenable the central plug 32 to be pressed home into the position shown inthe assembled view in Figure 7.

Once the two elements have been assembled as shown in Figure 7, they areboth pressed into the circular confining shell or band 40 unlike theband 22 in Figure 4. This band 40 is provided with a lower rim edge 41that stops short of the lower surface of the outer ring element 31, forpurposes of insulation. The tight pressure between the confining band 40and the two elements of the socket is sufficient, however, to hold thoseelements against removal from the socket by the sole friction forceengagement of the contact forks 19 on, and against, the pins of anyminiature electron tube that may be removed from the socket.

The tail pieces 21 will be bent under directly at the under surface ofthe ring 31 in the same manner as shown in Figure 5. Each contactterminal is thus anchored against removal when a tube is pulled out ofthe socket.

Various modifications in the structural design may be made to fitseveral pieces together and then bind them tightly together, whileleaving spaces suitably located and oriented to accommodate contactterminals for specific tubes and spacings required. It is contemplatedthat all such modifications may be made within the scope of theinvention as disclosed herein.

The contact fork 20 will be seated in each cavity in the circulararrangement, as shown in Figure 10, with the fork resting on theshoulder shelf or floor 37, and the tail piece 21 extending down througha passage 42, Figure 8, at the bottom of the space 35a.

What is claimed is:

1. A sub-miniature tube socket comprising two combshaped elements ofinsulating material having their respective teeth disposed to permit thetwo elements to be interfitted with the teeth of each element fittinginto the cavities of the other element, with the teeth of one combfalling short of fully filling the complementary cavities of the othercomb element to provide spaces of pre-determined dimensions foraccommodating pin-receiving terminals for the pins of a sub-miniaturetube, and means for holding the two combs tightly interfitted.

2. A sub-miniature tube socket comprising a hollow tubular section ofinsulating material, and a central plug section shaped and dimensionedto fit snugly within the tubular section, the two section being providedwith mortice and tenon interfitting cavities and extensions, the tenonextensions being slightly short of filling the mortice cavities to leaveclosely defined spaces for accommodating pin-receiving terminals for thepins of sub-miniature electronic tubes.

3. A sub-miniature socket for sub-miniature electronic tubes, comprisinga hollow tubular element provided with References Cited in the file ofthis patent UNITED STATES PATENTS 1,674,253 Lightfoot June 19, 19281,954,252 Maus Apr. 10, 1935 2,436,284 Bondon Feb. 17, 1948 2,443,706Jansen June 22, 1948 2,453,014 Jackson Nov. 2, 1948 FOREIGN PATENTS595,186 Great Britain Nov. 28, 1947 644,540 Great Britain Oct. 11, 1950

